AstraZeneca (AZN+0.2%) buys rights to Targacept's (TRGT-12%) experimental antidepressant (TC-5214) in a deal worth up to $1.24B, boosting its pipeline and slapping a big endorsement on its U.S. biotech partner's drug. Targacept will receive $200M upfront, $540M for reaching first commercial sale, and another $500M for hitting sales milestones.